Arc-lamp construction.



A. A. LOW.

ARC LAMP CONSTRUGTIQN.

APPLICATION FILED MAR.16, 1908.

Patented July 30, 1912.

Tiaqvi/lnwosco UNITED STATES PATENT- OFFICE,

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ARC-LAMP CONSTRUCTION.

Specification. of Letters Patent. P t t d J l 30, 1912,

Application filed March 16, 1908. Serial No. 421,568.

To all whom it may concern:

Be it known that I, ABBo'rA. Low, a citizen of the United States, and resident of Horseshoe, in the county of St. Lawrence and State of New York, have invented certain new and useful Improvements in Are- Lamp Construction, of which the following is a specification.

This invention relates to are lamps employing an' expansible thermal conductor for cont-rolling the feed'of the movable electrode or carbon. Such a thermal conductor,

being preferably in the form of a wire having sufiicient resistance to become heated by the passage of current therethrough, the resulting variations in expansion controlling the feed of the carbon, is naturally a somewhat delicate instrumentality for the purose. v

The object of the present invention is so to reduce the friction of the moving parts connected with this thermal conductor, that the condition of the mechanism may be termed floating.

To this end, the invention may be said't'o consist in the novel features hereinafter described, illustrated in the drawings, and more particularly set forth in the claims.

In the drawings, Figure 1 is a .side elevation of an arc lamp embodying the improvements; Fig. 2 is a horizontalsectio-n through the movable electrode carrier; Fig. 3 is a similar view of a modified form of carrier; Fig. 4 is -a horizontal section through the bearing for the lever connected immediately to the thermal conductor; Fig. 5 is a side view of this bearing; and Fig. 6 is a fractional, sectional view of a modified form of carbon carrier.

Referring to these drawings, theframe of the lamp, which may be considerably varied,

is shown .as comprising upright rods 1, top and bottom plates 2 and 3, and an intermediate plate or platform 4. Depending from the bottom plate 3 is the lower, fixed electrode holder 5; 6 being the fixed electrode.

7 is the'upper, movableelectrode holder, here shown as in the form of a split resili ent tube. This holder 7 is mounted in a block or carrier 8, the sides of which are grooved at 9 to receive the rods 1.

10 is themovable electrode in holder 7. The feed of electrode-10 is immediately controlled by a clutch 11, which embraces the electrode and rests upon the platform 4. From the end of this clutch member 11 a link 12 extends upward to the outer end of a lever 13, which is fixed to a rock-shaft 14 ournaled in a bracket 14 secured toone of the rods 1. Connected. to the lever 13 at opposite sides of its pivot is a thermal "con ductor or wire 15, the outer ends of-thisconductor being connected to spring supports 16. A compensating'wire17 also connects these spring supports, but, unlike conductor 15, is intended to carry no current. lCon ductor 15 and wire 17- are of such,.nature that they expand and contract equallyunder 4 the influence of variations in atmospheric temperature; therefore, such variations cause the wire 17 to vary theflexure of spring" supports 16 correspondingly, thus preventing the expansion and contraction of conductor 15, undervariations in atmospheric temperature, from". afiecting the: lever 13. The current for the lamp entersconductor 15 through variable resistance 18,

passes from the lower end of conductor 15.

to the holder 7 by wire 19, from, the holder 7 to and through the movable electrode 10,

the lower electrode 6, the fixed 'electr'ode holder -5, and out at 20. It will be understood that contraction of conductor 15, due

to a decrease in the amount of current'passing therethrough,"causes the conductor to turn the lever 13 in one direction; this movement lowering the link 12 and clutch 11, thus permitting the electrode 10 to slide downward under the influence of gravity.- The opposite movement of lever 13, and the lifting of clutch 11, to raise the movable electrode, is effected, when conductor 15 expands, owing to increase of current, by a weight 21, mounted on intermediately pivoted lever 22; this lever being connected with lever 13 by a link 23. l

All of the features thus far described form the subject matter of the co-pending application of Maurice J. Wohl and Harry Hertzberg, filed Dec. 4th, 1907, Serial No. 405,068, and are not claimed per se in the present case.

The features of novelty in the present. ap plication will now be described. I

Fig. 2 shows the block or carrier 8 as of insulating material; Fig. 3 as of metal or other conducting material. It is desired to .de insulating ball bearing between i a look and the rods 'imin the friction I e i rods. Lin Fig. 2, each groove is "1101 n as being provided horizont ily alined pairs of substantially semi-spherical recesses 25, there being preferably a pair toward the top of the groove another pair toward the bottom thereof. In these recesses are seated steel or other balls 27, which bear against the rods 1. In Fig, 3 glass balls 2 8 are similarly disposed, being held in position by a trough-shaped retainer plate 29, which fits in each groove 9, being itself held in place by a screw or screws 30. These plates are provided with apertures registering with the recesses 25: and it will be observed that the complete recesses formed in the block 8 and in the plates are somewhat more than semi-spherical, so that, when the plates are secured in position, the balls are prevented from falling out, even when the block is removed from the rods 1. It is also desired to reduce the friction at the pivot of lever 13. This may be effected in the following manner: In each of the journal apertures of the two cheeks of the bracket 14, between which stands the lever 13, is secured a ball race-way 31, preferably of insulating material. This race-way may be desirably formed of two annular sections 32, each having half of the race-way groove, and being further provided with a flange 33, the two flanges overlying the opposite sides of the cheek of the bracket. The two sections 32 are shown as being secured in position by small bolts, or the like, 34, which pass through the flanges 33 and the checks of the bracket. In the race-ways are the balls 35, upon which'rest the ends of the rock-shaft 14. It will thus be seen that the friction of the moving parts connected to the conductor 15 is greatly reduced, thereby much enhancing the reliability of the action of said conductor.

in 8 is illustrated a modified form v ble electrode carrier .0, of insulan is divided vertically in three secand 43; the junction planes cutting the several recesses ie, which are slightly more than semi-spherical. in this way, the balls are held against egress, and yet are easily insertible during the assembling of the carrier 40. A further advantage is that the recesses 14 may be ground out more truly than when they are formed in an integral block. The several sections of the carrier may be secured together, as by bolts 46.

What is claimed as new is:

1. In combination withan arc lamp frame ihaving upright guide rods and a movable electrode, of a carrier block for said electrode having grooves receiving said rods and partially spherical recesses communicating with said grooves, antifriction insulating balls mounted in said recesses and bearing against said rods, and troughshaped retainer plates fitting and secured in said grooves and having apertures communicating with said recesses, said apertures being sufficiently small to prevent egress of the balls from the recesses.

52. In combination with an arc lamp frame having parallel upright guide rods and a movable electrode, of a movable carrier block for said electrode having grooves at either end receiving said rods and recesses communicating with said grooves, antifriction balls of insulating material mounted in said recesses to engage said rods and to separate said block therefrom.

Signed at New York city in the county of Kings and State of New York this 12th day of March A. D. 1908.

ABBOT A. I OW. 

